Write-once type optical disc, and method and apparatus for managing defective areas on write-once type optical disc

ABSTRACT

A recording medium of writable once type, and a method and apparatus for managing a defective area on the recording medium are provided. The method includes detecting an existence of a defective area within a data area of the recording medium once data are written onto the data area in a data writing operation, writing data written in the defective area onto another area of the data user if the defective area is detected, and writing, onto at least one defect management area on the recording medium, defect management information associated with the defective area.

[0001] This application claims the priority benefit of the Korean PatentApplication Nos. P2002-058515 filed on Sep. 26, 2002, and P2003-001856filed on Jan. 11, 2003, the entire contents of which are herein fullyincorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an optical disc of write-oncetype, such as a Blu-ray Disc Write Once (BD-WO), and a method andapparatus for managing a defective area on the write-once type opticaldisc.

[0004] 2. Background of the Related Art

[0005] A new type of high density optical disc such as a Blu-ray DiscRewritable (BD-RE) is being developed. A benefit of the BD-RE is that ithas a rewritable capability where the quality video and audio data canbe written, erased and rewritten thereon repeatedly.

[0006]FIG. 1 is a block diagram of a general optical disc device forwriting/reproducing data to/from an optical disc such as a BD-RE. Asshown in FIG. 1, the optical disc device includes an optical pickup 11for recording/reproducing a signal to/from a BD-RE 10, a video discrecorder (VDR) system 12 for processing a signal from the optical pickup11 as a reproduced signal, or demodulating and processing an externaldata stream into a writable signal suitable for writing onto the BD-RE10, and an encoder 13 for encoding an external analog signal andproviding the encoded signal to the VDR system 12.

[0007]FIG. 2 shows a structure of a related art BD-RE. Referring to FIG.2, the BD-RE is divided into a Lead-In Area (LIA), a data area, and aLead-Out area (LOA), with an Inner Spare Area (ISA) and an Outer SpareArea (OSA) assigned to a fore end and a rear end of the data area.

[0008] Referring to FIGS. 1 and 2, the VDR system 12 of the optical discdevice writes in the data area of the BD-RE the external data inclusters corresponding to an ECC block unit having a predetermined sizeof recording, after the VDR system 12 encodes and demodulates theexternal signal into a signal suitable for writing. During the writingprocess, if there is a defective area found in the data area of theBD-RE, the VDR system 12 carries out a series of replacement writingoperations in which the clusters of data written onto the defective areais written onto one of the spare areas, e.g., on the ISA in place of thedefective area. Therefore, even if there is a defective area in the dataarea of the BD-RE, the VDR system 12 can prevent a data writing error inadvance by writing the clusters of data written in the defective areaonto the spare area.

[0009] A Blu-ray Disc Write-Once (BD-WO) is another type of high densityoptical disc that is being developed where a high quality of data can berecorded and reproduced to/from the disc. As the name may suggest, datacan be written only once on the BD-WO and is not rewritable on theBD-WO, but the BD-WO can be read repeatedly. As a result, the BD-WO isuseful where the rewritability of data on a recording medium is notdesired.

[0010] Unfortunately, since the BD-WO is still in the early developmentstage, there are no schemes, no disc structures, no apparatuses and nomethods on how to manage the defective areas of the BD-WO, which will beneeded for the BD-WO to be commercially viable and operationallyfeasible.

SUMMARY OF THE INVENTION

[0011] Accordingly, the present invention is directed to a technique formanaging a defective area on an optical disc of write-once type such asa BD-WO.

[0012] An object of the present invention is to provide a write-oncetype optical disc, and an apparatus and method for effectively managinga defective area of the write-once type optical disc.

[0013] Additional features and advantages of the invention will be setforth in the description which follows, and in part will be apparent tothose having ordinary skill in the art upon examination of the followingor may be learned from practice of the invention. The objectives andother advantages of the invention will be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

[0014] According to an aspect of the invention, a method for managing adefective area on a recording medium of writable once type, therecording medium including a data area, includes (a) detecting anexistence of a defective area within the data area of the recordingmedium once data are written onto the data area in a data writingoperation; (b) writing data written in the defective area onto anotherarea of the data user if the defective area is detected; and (c)writing, onto at least one defect management area on the recordingmedium, defect management information associated with the defectivearea.

[0015] According to another aspect of the invention, a method formanaging a defective area on a recording medium of writable once type,the recording medium including a data area and a lead-in area, the dataarea including a spare area, includes (a) detecting an existence of adefective area within the data area of the recording medium afterwriting data onto the data area in a data writing operation; (b) writingdata written in the defective area onto the spare area if the defectivearea is detected; and (c) writing, onto the lead-in area, defect listinformation associated with the defective area.

[0016] According to another aspect of the invention, a recording mediumof writable once type, includes a data area including a recording area,a replacement area, and at least one defect management area, wherein anexistence of a defective area within the data area of the recordingmedium is detected after data are written onto the recording area duringa data writing operation, data written in the defective area are writtenonto the replacement area if the defective area is detected, and defectmanagement information associated with the defective area is writtenonto the at least one defect management area.

[0017] According to another aspect of the invention, a recording mediumof writable once type, includes a data area including a spare area; anda lead-in area, wherein an existence of a defective area within the dataarea of the recording medium is detected after writing data onto thedata area in a data writing operation, data written in the defectivearea is written onto the spare area if the defective area is detected,and defect list information associated with the defective area iswritten onto the lead-in area.

[0018] According to another aspect of the invention, an apparatus formanaging a defective area on a recording medium of writable once type,the recording medium including a data area, includes (a) a configuredsection for detecting an existence of a defective area within the dataarea of the recording medium once data are written onto the data area ina data writing operation; (b) a configured section for writing datawritten in the defective area onto another area of the data user if thedefective area is detected; and (c) a configured section for writing,onto at least one defect management area on the recording medium, defectmanagement information associated with the defective area.

[0019] According to another aspect of the invention, an apparatus formanaging a defective area on a recording medium of writable once type,the recording medium including a data area and a lead-in area, the dataarea including a spare area, includes (a) a configured section fordetecting an existence of a defective area within the data area of therecording medium after writing data onto the data area in a data writingoperation; (b) a configured section for writing data written in thedefective area onto the spare area if the defective area is detected;and (c) a configured section for writing, onto the lead-in area, defectlist information associated with the defective area.

[0020] It is to be understood that both the foregoing description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention claimed.

BRIEF DESCRITPION OF THE DRAWINGS

[0021] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this application, illustrate embodiment(s) of theinvention and together with the description serve to explain theprinciple of the invention. In the drawings:

[0022]FIG. 1 illustrates a related art optical disc deviceschematically;

[0023]FIG. 2 illustrates a structure of a related art BD-RE;

[0024]FIG. 3 illustrates a block diagram of an optical discrecording/reproducing device according to the present invention;

[0025]FIGS. 4A and 4B illustrate a structure of a single layer BD-WO anda dual layer BD-WO, respectively, according to an embodiment of thepresent invention;

[0026]FIG. 5 illustrates a method of managing a defective area on aBD-WO in accordance with a first preferred embodiment of the presentinvention;

[0027]FIGS. 6A and 6B illustrate the method of managing a defective areaon a BD-WO in accordance with a variation of the first preferredembodiment of the present invention;

[0028]FIG. 7 illustrates a method of managing a defective area on aBD-WO in accordance with a second preferred embodiment of the presentinvention;

[0029]FIG. 8 illustrates a method of managing a defective area on aBD-WO in accordance with a third preferred embodiment of the presentinvention;

[0030]FIG. 9 illustrates a method of managing a defective area on aBD-WO in accordance with a fourth preferred embodiment of the presentinvention; and

[0031]FIGS. 10A, 10B and 10C illustrate a method of managing a defectivearea on a BD-WO in accordance with various examples of a fifth preferredembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Reference will now be made in detail to the preferred embodimentsof the present invention, examples of which are illustrated in theaccompanying drawings.

[0033]FIG. 3 is an example of a block diagram of an optical discrecording/reproducing device 20 according to an embodiment of thepresent invention. The optical disc recording/reproducing device 20includes an optical pickup 22 for writing/reading data to/from anoptical recording medium 21, a servo unit 23 for controlling the pickup22 to maintain a distance between an objective lens of the pickup 22 andthe recording medium 21 and for tracking relevant tracks on therecording medium 21, a data processor 24 for processing and supplyinginput data to the pickup 22 for writing, and for processing data readfrom the recording medium 21, an interface for exchanging data and/orcommands with any external host 30, a memory or storage 27 for storinginformation and data therein including defect management data associatedwith the recording medium 21, and a microprocessor or controller 26 forcontrolling the operations and elements of the recording/reproducingdevice 20. Data to be written/read to/from the recording medium 21 mayalso be stored in the memory 27. All the components of therecording/reproducing device 20 are operatively coupled.

[0034] The recording medium 21 is a recording medium of write-once typesuch as a BD-WO.

[0035]FIGS. 4A and 4B illustrate respectively a structure of two typesof a write-once optical disc such as a BD-WO according to the presentinvention. As shown in FIGS. 4A and 4B, the BD-WO can have one or tworecording layers. In FIG. 4A, a BD-WO having only a single recordinglayer (Layer 0) includes a single recording layer composed of a lead-inarea (LIA), a data area, and a lead-out area (LOA), and is referred toherein as a single layer disc. In FIG. 4B, a dual layer BD-WO includestwo recording layers (Layers 0 and 1). The first recording layer (Layer0) includes a LIA, a data area, and an outer zone. The second recordinglayer (Layer 1) includes a LOA, a data area and an outer zone, and isreferred to herein as a dual layer disc. Generally, a data writingoccurs in the direction shown with the dotted arrow in the dual layerdisc. The single layer disc can have a capacity of 23.3, 25.0 or 27.0Gbytes, whereas the dual layer disc can have a capacity of 46.6, 50.0,or 54.0 Gbytes.

[0036] It should be noted that all the different embodiments of thepresent invention (e.g., various methods discussed below) are applicableto any type of a write-once optical disc, such as a single layer BD-WOor a dual layer BD-WO. Further, although the use of therecording/reproducing device 20 of FIG. 3 is discussed below inconjunction with the methods of the invention, the invention is notlimited to such and encompasses other recording/reproducing devices aslong as they are configured to implement the present methods. Forinstance, the device shown in FIG. 1 may be used to implement thepresent methods as needed.

[0037]FIG. 5 illustrates a method for managing a defective area on aBD-WO in accordance with a first preferred embodiment of the presentinvention.

[0038] Referring to FIGS. 3 and 5, the method of managing a defectivearea of a write-once optical disc according to the first embodiment ofthe present invention is as follows. The optical discrecording/reproducing device 20 writes data continuously on apredetermined writing sector in the data area of the BD-WO, where awriting sector may be set to be a Defect Verify Unit (DVU) of a certainrecording size equivalent to one or more than one physical track orcluster on the BD-WO.

[0039] After continuously writing the data on the DVUs for a set of data(Recording 1), the microcomputer 26 controls the pickup 22 to conduct aseries of defective area detecting operations on the Recording 1 area ofthe BD-WO. A defective area detecting operation involves reproducing thedata written in a DVU and verifying that the data was properly writtenon the DVU by, e.g., comparing the actual data reproduced from the DVUwith the data that was meant to be written on the DVU. If theverification result indicates that certain data was not properlyrecorded on a DVU, then the recording/reproducing device 20 assumes thatthere is a defective area in that DVU of the BD-WO and rewrites the data(directed to the defective DVU) on a next available recording area onthe BD-WO using a linear replacement scheme.

[0040] For example, after writing first to fifth clusters of data(Clusters #1˜#5) continuously as a first defect verify unit DVU #1 (stepS10), the microcomputer 26 controls the pickup 22 to reproduce the datawritten on DVU #1 progressively (e.g., cluster by cluster), and detectsif there is any defective area in DVU #1 by examining the reproduceddata. If, for example, a defective area is detected in the secondcluster Cluster #2 (step S11), the microcomputer 26 controls the dataprocessor 24 and the pickup 22 to carry out a replacement writingoperation. In the replacement writing operation, the data written toCluster #2, which are temporarily stored in the memory 27 or some otherstorage, are written onto a cluster area succeeding the fifth clusterCluster #5 (step S12).

[0041] After the replacement writing for Cluster #2 is completed, therecording/reproducing device 20 checks the next cluster and so on untilthe last cluster in that DVU is checked. If, for example, a defectivearea is detected from the fourth cluster Cluster #4 (S13), therecording/reproducing device 20 carries out a replacement writingoperation as discussed above to write the data written in the defectiveCluster #4 onto a next available cluster area, e.g., a cluster areasucceeding the replacement area for Cluster #2 (step S14).

[0042] The replacement writing operations continue until data on all thedefective clusters in the DVU are written in other cluster areas(replacement areas). As a result, in this example, DVU #1 ends up havingClusters #1, #3, and #5 and two defective areas (original Clusters #2and #4), where the replacement areas are used to write data thereon inlieu of the two defective areas using a linear replacement scheme.

[0043] Once the data recording (Recording 1) having a temporalcontinuity ends (which includes the defective area detection operationsand replacement writing operations for DVU #1, DVU #2, . . . , DVU #n),the microcomputer 26 writes management information onto an area 32following the last DVU of Recording 1.

[0044] The management information is used to manage the defective areasin the data area of the BD-WO and to manage the data written in thereplacement areas corresponding to the defective areas. The managementinformation may be managed as Defect List (DFL) information, wherein theDFL information may include one or a plurality of defect entriesDefect_Entry #1-Defect_Entry #m, each defect entry having a firstphysical sector number of a corresponding defective area (PSN ofDefective), a first physical sector number of a replacement areacorresponding to that defective area (PSN of Replacement), and any otherdata pertaining to a defect entry.

[0045] Once the writing of the DFL information (e.g., DFL #1) forRecording 1 is completed, the recording/reproducing device 20 maycontinue with another data writing operation (e.g., Recording 2) havinga temporal continuity. When the data writing operation (Recording 2)ends (which includes the defective area detecting operations and thereplacement writing operations for all the DVUs of Recording 2 asdiscussed above), the management information for Recording 2 is writtenin an area 33 following the last DVU in Recording 2. This process isrepeated as long as all the data to be written in the data area of theBD-WO are properly written.

[0046] For fast access to the management information written thus far,the microcomputer 26 may be configured to write fast access informationin other parts of the BD-WO. For instance, the fast access informationcontaining a physical sector number of the defect list written thereon(PSN of Defect List) may be written on the LIA of the BD-WO as DiscDefinition Structure (DDS) information. That is, the physical sectornumber of the DFL #1 (area 32), the physical sector number of the DFL #2(area 33), and so on are stored in the LIA as part of the DDS. In thealternative, once all the defect lists (e.g., DFL #1-DFL #i) are writtenscattered throughout the data area of the BD-WO according to the datawriting operations, the location information (e.g., physical sectornumber) of these defect lists may be stored in the LIA as part of theDDS. According to these configurations, during a data reproducingoperation, a recording/reproducing device can read and refer to the DDSinformation written in the LIA to locate where the DFLs are located inthe data area of the BD-WO. Then the DFLs can be searched to locate andreproduce data written in a replacement area corresponding to a desiredarea that is defective.

[0047] As shown in FIG. 5, in the first embodiment, there is nopre-assigned spare area in the data area of the BD-WO. DFLs as storedare scattered throughout the data area as the recording operationsprogress.

[0048]FIGS. 6A and 6B illustrate the method for managing a defectivearea on a BD-WO in accordance with a variation of the first preferredembodiment of the present invention. This variation of the firstembodiment is identical to the above discussed first embodiment (FIG.5), except that the BD-WO includes a spare area of a fixed size assignedinitially to a front part (ISA) or rear end part of the data area, e.g.,during the disc production. In this example, an Outer Spare Area 34(OSA) assigned to the rear end part of the data area is shown.

[0049] In this variation, the spare area (e.g., OSA 34) has a fixed sizeinitially, but is variable depending on the need to use the spare areaduring a data writing/recording operation. For instance, as defects inthe data area increase, the size of the assigned spare area may bedecreased because the writing of data in the data writing operation(s)is pushed into the spare area, thereby reducing the size of the sparearea. That is, in this variation of the first embodiment, the spare areais assigned and used as a designated extra space for the data writingoperations, and not necessarily as a replacement area onto which data ofthe defective area may be written using a linear replacement scheme.

[0050] For instance, as shown in FIGS. 6A and 6B, the recording size ofthe data area (excluding the OSA 34) is reduced according to therecording size of replacement areas (e.g., the size of replacementClusters #2 and #4) and the size of DFLs as the defective area detectingoperation and replacement writing operation are progressed. In thisaspect, if the final written location of the data in the user data(excluding the OSA 34) does not protrude into the starting writtenlocation of the OSA 34 assigned at the initial stage of disc production,the recording size of the data area (excluding the OSA 34) is maintainedas it is. But if the final written location of the data in the user dataexceeds the starting written location of the OSA 34 assigned at theinitial stage of disc production, the recording size of the user data(excluding the OSA 34) will be increased and the size of the OSA 34 willbe decreased accordingly.

[0051] Thus, by assigning and using the OSA 34 having a variablyreducible recording size, the recording/reproducing device 20 canminimize any error between a writable data capacity detected beforestarting a data writing operation and the actual writable data capacityreduced due to the presence of any defective area in the data area ofthe disc.

[0052]FIG. 7 illustrates a diagram showing a method for managing adefective area on a BD-WO in accordance with a second preferredembodiment of the present invention. In the second embodiment, the BD-WOincludes a spare area assigned to a front part (Inner Spare Area ISA)and/or to a rear end part (Outer Spare Area OSA) of the data area. InFIG. 7, the Outer Spare Area 35 (OSA) is shown. The spare area (e.g.,OSA 35) in the second embodiment is different from the spare area (e.g.,OSA 34) in the first embodiment, because the spare area in the secondembodiment is used as a replacement area for writing data correspondingto a defective area using a linear replacement scheme. The spare area inthe second embodiment has a variable size, but can have a fixed size ifdesired.

[0053] Referring to FIG. 7, the recording/reproducing device 20 carriesout a replacement writing operation wherein, after writing first tofifth clusters of data (Clusters #1˜#5) in succession as a first defectverify unit DVU #1 (step S11), the defective area detecting operationand the replacement writing operation are performed. If a defective areafrom the second cluster area (Cluster #2) is found, then the data of thesecond cluster is also written in an area 35 a of the OSA 35 (step S22)according to a linear replacement scheme. Subsequently, if a defectivearea from the fourth cluster (Cluster #4) is found, then the data of thefourth cluster is written in an area 35 b of the OSA 35 (step S24)according to a linear replacement scheme. Any data on a defective areadiscovered in each of DVUs is rewritten in a corresponding area of thespare area such as the OSA 35 using the linear replacement scheme.

[0054] As a result, in this example, the first defect verify unit DVU#1has first, third, and fifth clusters (Clusters #1, #3, and #5) writtennormally therein and two defective areas (Clusters #2 and #4). The OSA35 has the replacement areas 35 a and 35 b for storing therein dataequal to the data of defective Clusters #2 and #4.

[0055] As in the first embodiment, the second embodiment of theinvention writes the management information scattered throughout thedata area of the disc once each data recording (e.g., Recording 1,Recording 2, etc.) with a temporal continuity ends. For instance, therecording/reproducing device 20 writes DFL information (i.e., DFL #1) asthe management information onto an area 32 following the last DVU ofRecording 1. The operation of writing management information (e.g.,DFLs) and the operation of writing DDS (e.g., for fast access) are thesame as those discussed in the first embodiment of the invention.

[0056]FIG. 8 illustrates a diagram showing a method for managing adefective area on a BD-WO in accordance with a third preferredembodiment of the present invention. The third embodiment is identicalto the second embodiment of the invention, except that the DFLs(management information) are not stored as scattered throughout the dataarea, but instead, the DFL(s) are stored within an assigned spare areasuch as an ISA or OSA.

[0057] As shown in FIG. 8, for example, after each data recording (e.g.,Recording 1) with a temporal continuity ends, the recording/reproducingdevice 20 writes a DFL corresponding to just ended data recording,within the OSA 35. Thus, all the DFLs corresponding to differentRecordings 1, 2, . . . are stored in an area of the OSA 35. In addition,the OSA 35 functions as replacement areas for storing data identical tothe data of any defective area in the data area. Having the DFLs withinone area such as the OSA 35 and having the replacement areas all withinthe OSA 35 can expedite the process of locating desired replacementareas using the DDS and DFLs.

[0058]FIG. 9 illustrates a diagram showing a method for managing adefective area on a BD-WO in accordance with a fourth preferredembodiment of the present invention. The fourth embodiment is identicalto the third embodiment of the invention, except that the DFLs(management information) are written in a particular writing sectoroutside of the data area, for example, in the lead-in area LIA.

[0059] As shown in FIG. 9, for example, after each data recording (e.g.,Recording 1) with a temporal continuity ends, the recording/reproducingdevice 20 writes a DFL corresponding to just ended data recording,within the LIA 36. Thus, all the DFLs corresponding to differentRecordings 1, 2, . . . are stored in the LIA 36. In addition to theDFLs, the LIA 36 stores therein the DDS discussed in the previousembodiments. The OSA 35 still functions as replacement areas for storingdata identical to the data of any defective area in the data area.Having the DFLs within one area such as the LIA 36, having thereplacement areas all within the OSA 35, and/or having both the DDS andDFLs within one area such as the LIA 36 expedites the process of defectmanagement and the process of locating desired replacement areas usingthe DDS and DFLs.

[0060]FIGS. 10A, 10B and 10C are examples for illustrating a method formanaging a defective area on a BD-WO according to a fifth preferredembodiment of the present invention. The fifth embodiment differs fromthe previous embodiments in that it allows a cumulative writing of DFLs.This cumulative writing of DFLs is applicable to each of the firstthrough fourth embodiments previously discussed.

[0061] As an example, according to the fifth embodiment, FIG. 10A showshow the cumulative writing of DFLs is applied to the first and secondembodiments shown in FIGS. 5-7. Referring to FIG. 10A, when a first datawriting operation (e.g., Recording 1) having a temporal continuity ends,the recording/reproducing device 20 writes a DFL (DFL #1) correspondingto the just ended, first writing operation onto a first DFL area 37 ofthe data area. As discussed in the first and second embodiments, thefirst DFL area 37 follows immediately the last DVU of the firstrecording area (an area of Recording 1). Then the recording/reproducingdevice 20 proceeds with a second data writing operation (i.e., Recording2). After the second data writing operation ends, therecording/reproducing device 20 writes a DFL (DFL #2) corresponding tothe second writing operation along with the first DFL (DFL #1) onto aDFL area 38 of the data area. The second DFL area 38 follows immediatelythe last DVU of the second recording area (area of Recording 2). Thenthe recording/reproducing device 20 proceeds with a third data writingoperation (i.e., Recording 3). After the third data writing operationends, the recording/reproducing device 20 writes a DFL (DFL #3)corresponding to the third writing operation along with the first andsecond DFLs (DFLs #1 and #2) onto a third DFL area 39 of the data area.The third DFL area 39 follows immediately the last DVU of the thirdrecording area (area of Recording 3). This process continues for anysubsequent data writing operation. Accordingly, the DFLs arecumulatively written within the data area as the data writing operationscontinue.

[0062] As another example, according to the fifth embodiment, FIG. 10Bshows how the cumulative writing of DFLs is applied to the thirdembodiment shown in FIG. 8 where the DFLs are written within a sparearea such as the OSA 35. Referring to FIG. 10B, when a first datawriting operation (e.g., Recording 1) having a temporal continuity ends,the recording/reproducing device 20 writes a DFL (DFL #1) correspondingto the just ended, first writing operation onto a DFL area 35 d of theOSA 35. Then the recording/reproducing device 20 proceeds with a seconddata writing operation (i.e., Recording 2). After the second datawriting operation ends, the recording/reproducing device 20 writes a DFL(DFL #2) corresponding to the second writing operation along with thefirst DFL (DFL #1) onto a second DFL area 35 e of the OSA 35. In thisexample, the second DFL area 35 e is immediately adjacent to the firstDFL area 35 d. Then the recording/reproducing device 20 proceeds with athird data writing operation (i.e., Recording 3). After the third datawriting operation ends, the recording/reproducing device 20 writes a DFL(DFL #3) corresponding to the third writing operation along with thefirst and second DFLs (DFLs #1 and #2) onto a third DFL area 35 f of theOSA 35. In this example, the third DFL area 35 f follows immediately thesecond DFL area 35 e. This process continues for any subsequent datawriting operation. Accordingly, the DFLs are cumulatively written withinthe spare area of the data area as the data writing operations continue.

[0063] As still another example, according to the fifth embodiment, FIG.10C shows how the cumulative writing of DFLs is applied to the fourthembodiment shown in FIG. 9 where the DFLs are written within an areaoutside of the data area, e.g., a lead-in area LIA 36. Referring to FIG.10C, when a first data writing operation (e.g., Recording 1) having atemporal continuity ends, the recording/reproducing device 20 writes aDFL (DFL #1) corresponding to the first writing operation onto a DFLarea 36 a of the LIA 36. Then the recording/reproducing device 20proceeds with a second data writing operation (i.e., Recording 2). Afterthe second data writing operation ends, the recording/reproducing device20 writes a DFL (DFL #2) corresponding to the second writing operationalong with the first DFL (DFL #1) onto a second DFL area 36 b of the LIA36. In this example, the second DFL area 36 b is immediately adjacent tothe first DFL area 36 a. Then the recording/reproducing device 20proceeds with a third data writing operation (i.e., Recording 3). Afterthe third data writing operation ends, the recording/reproducing device20 writes a DFL (DFL #3) corresponding to the third writing operationalong with the first and second DFLs (DFLs #1 and #2) onto a third DFLarea 36 c of the LIA 36. In this example, the third DFL area 36 cfollows immediately the second DFL area 36 b. This process continues forany subsequent data writing operation. Accordingly, the DFLs arecumulatively written within an area before/after the data area, such asa lead-in area as the data writing operations continue.

[0064] In the fifth embodiment, by accessing the last DFL area of a dataarea, a spare area or a lead-in area, the DFLs associated with all thedata writing operations can be advantageously and immediately accessed.Therefore, even when the first defect list information (DFL #1) writtenat the time the first data writing operation (Recording 1) is not readproperly, DFL #1 information can be accessed by reading any subsequentDFL information. This prevents or minimizes an occurrence ofreproduction errors which may be caused by a damage to any defect list.

[0065] The application of the method for cumulative writing and managingthe defect list information may be extended to other embodiments forwriting and managing defect list information in addition to theforegoing various embodiments described with reference to FIGS. 3 to 9.

[0066] In the present invention, the data reproducing operation canoccur currently, subsequently or prior to the data writing operation.The data writing operation can occur currently, subsequently or prior tothe defect detecting operation and/or data replacement writing operationand/or the management information writing operation.

[0067] As has been described, the method and apparatus for managing adefective area on an optical disc of write once type according to thepresent invention read and reproduce properly a data written on adefective area of an optical disc such as BD-WO in a data reproductionby writing the data onto a spare area or other data area in place of thedefective area and by managing the data associated with the defectivearea and the defect management data effectively. The invention alsominimizes an error between a writable data capacity of a recordingmedium detected before starting the data writing operation and theactual writable data capacity of the recording medium reduced due to thedefective area, and minimizes any occurrence of reproduction errorswhich may be caused by a damage to a defect list.

[0068] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A method for managing a defective area on arecording medium of writable once type, the recording medium including adata area, the method comprising: (a) detecting an existence of adefective area within the data area of the recording medium once dataare written onto the data area in a data writing operation; (b) writingdata written in the defective area onto another area of the data area ifthe defective area is detected; and (c) writing, onto at least onedefect management area on the recording medium, defect managementinformation associated with the defective area.
 2. The method as claimedin claim 1, further comprising: (d) writing clusters of data onto afirst recording area of the data area during a first data writingoperation, each cluster of data being written to one of a plurality ofcluster areas of the first recording area; and wherein the detectingstep (a) includes: for each of the cluster areas, examining data writtentherein and determining whether the corresponding cluster area isdefective based on the examination result.
 3. The method as claimed inclaim 2, wherein the writing step (b) includes: writing data written ona corresponding cluster area of the first recording area, onto anothercluster area of the data area, if the determining step determines thatthe corresponding cluster area is defective.
 4. The method as claimed inclaim 3, wherein the writing step (c) includes: after the writing step(b) is completed for the first data writing operation, writing defectmanagement information associated with all the defective cluster areasof the first recording area, onto the at least one defect managementarea on the recording medium.
 5. The method as claimed in claim 1,wherein in the writing step (c), the defect management informationincludes a plurality of defect lists, each of the defect listsassociated with one of a plurality of recording areas of the data area.6. The method as claimed in claim 5, wherein the defect lists arewritten scattered throughout the data area according to data writingoperations.
 7. The method as claimed in claim 6, wherein the recordingmedium includes a pre-assigned spare area within the data area.
 8. Themethod as claimed in claim 7, wherein in the writing step (b), theanother area of the data area is the pre-assigned spare area.
 9. Themethod as claimed in claim 6, wherein each of the defect lists containsa present defect list and any previous defect list, such that each ofthe defect lists becomes a cumulative defect list.
 10. The method asclaimed in claim 1, wherein in the writing step (c), the at least onedefect management area on the recording medium is part of a pre-assignedspare area within the data area of the recording medium.
 11. The methodas claimed in claim 10, wherein the pre-assigned spare area is either aninner spare area located at a front part of the data area, or an outerspare area located at a rear end of the data area.
 12. The method asclaimed in claim 10, wherein in the writing step (b), the another areaof the data area is part of the pre-assigned spare area.
 13. The methodas claimed in claim 10, wherein in the writing step (c), the defectmanagement information includes a plurality of defect lists, each of thedefect lists associated with one of a plurality of recording areas ofthe data area, and wherein each of the defect lists contains a presentdefect list and any previous defect list such that each of the defectlists becomes a cumulative defect list.
 14. The method as claimed inclaim 1, wherein in the writing step (c), the at least one defectmanagement area on the recording medium is an area outside of the dataarea on the recording medium.
 15. The method as claimed in claim 1,wherein the defect management information includes positionalinformation on the defective area and positional information on theanother area of the data area used in the writing step (b).
 16. Themethod as claimed in claim 1, further comprising: (e) writing discdefinition structure information onto a lead-in area of the recordingmedium, the disc definition structure information containing positionalinformation associated with the defect management information.
 17. Themethod as claimed in claim 1, wherein the recording medium is a Blu-rayDisc Write Once (BD-WO).
 18. A method for managing a defective area on arecording medium of writable once type, the recording medium including adata area and a lead-in area, the data area including a spare area, themethod comprising: (a) detecting an existence of a defective area withinthe data area of the recording medium after writing data onto the dataarea in a data writing operation; (b) writing data written in thedefective area onto the spare area if the defective area is detected;and (c) writing, onto the lead-in area, defect list informationassociated with the defective area.
 19. The method as claimed in claim18, wherein the recording medium is a Blu-ray Disc Write Once (BD-WO).20. The method as claimed in claim 18, wherein in the writing step (c),the defect list information includes a plurality of defect lists eachassociated with one of a plurality of recording areas of the data area,and each of the defect lists contains a present defect list and anyprevious defect list such that each of the defect lists becomes acumulative defect list.
 21. A recording medium of writable once type,comprising: a data area including a recording area, a replacement area,and at least one defect management area, wherein an existence of adefective area within the data area of the recording medium is detectedafter data are written onto the recording area during a data writingoperation, data written in the defective area are written onto thereplacement area if the defective area is detected, and defectmanagement information associated with the defective area is writtenonto the at least one defect management area.
 22. The recording mediumas claimed in claim 21, wherein the recording area includes a pluralityof cluster areas, wherein clusters of data are written onto therecording area during a first data writing operation, each cluster ofdata being written to one of the cluster areas of the recording area,and for each of the cluster areas, data written therein is examined todetermine whether the corresponding cluster area is defective.
 23. Therecording medium as claimed in claim 22, wherein data written on acorresponding cluster area of the recording area, is written ontoanother cluster area of the data area, if the corresponding cluster areais determined to be defective.
 24. The recording medium as claimed inclaim 23, wherein defect management information associated with all thedefective cluster areas of the recording area is written onto the atleast one defect management area on the recording medium.
 25. Therecording medium as claimed in claim 21, wherein the defect managementinformation includes a plurality of defect lists, each of the defectlists associated with one of a plurality of recording areas of the dataarea.
 26. The recording medium as claimed in claim 25, wherein thedefect lists are written scattered throughout the data area according todata writing operations.
 27. The recording medium as claimed in claim26, wherein the recording medium further includes a pre-assigned sparearea within the data area.
 28. The recording medium as claimed in claim27, wherein the replacement area of the data area is the pre-assignedspare area.
 29. The recording medium as claimed in claim 26, whereineach of the defect lists contains a present defect list and any previousdefect list, such that each of the defect lists becomes a cumulativedefect list.
 30. The recording medium as claimed in claim 21, whereinthe at least one defect management area on the recording medium is partof a pre-assigned spare area within the data area of the recordingmedium.
 31. The recording medium as claimed in claim 30, wherein thepre-assigned spare area is either an inner spare area located at a frontpart of the data area, or an outer spare area located at a rear end ofthe data area.
 32. The recording medium as claimed in claim 30, whereinthe replacement area of the data area is part of the pre-assigned sparearea.
 33. The recording medium as claimed in claim 30, wherein thedefect management information includes a plurality of defect lists, eachof the defect lists associated with one of a plurality of recordingareas of the data area, and wherein each of the defect lists contains apresent defect list and any previous defect list such that each of thedefect lists becomes a cumulative defect list.
 34. The recording mediumas claimed in claim 21, wherein the at least one defect management areaon the recording medium is an area outside of the data area on therecording medium.
 35. The recording medium as claimed in claim 21,wherein the defect management information includes positionalinformation on the defective area and positional information on thereplacement area of the data area.
 36. The recording medium as claimedin claim 21, further comprising: a lead-in area located outside of thedata area and carrying disc definition structure information includingpositional information associated with the defect managementinformation.
 37. The recording medium as claimed in claim 21, whereinthe recording medium is a Blu-ray Disc Write Once (BD-WO).
 38. Arecording medium of writable once type, comprising: a data areaincluding a spare area; and a lead-in area, wherein an existence of adefective area within the data area of the recording medium is detectedafter writing data onto the data area in a data writing operation, datawritten in the defective area is written onto the spare area if thedefective area is detected, and defect list information associated withthe defective area is written onto the lead-in area.
 39. The recordingmedium as claimed in claim 38, wherein the recording medium is a Blu-rayDisc Write Once (BD-WO).
 40. The recording medium as claimed in claim38, wherein the defect list information includes a plurality of defectlists each associated with one of a plurality of recording areas of thedata area, and each of the defect lists contains a present defect listand any previous defect list such that each of the defect lists becomesa cumulative defect list.
 41. An apparatus for managing a defective areaon a recording medium of writable once type, the recording mediumincluding a data area, the apparatus comprising: (a) means for detectingan existence of a defective area within the data area of the recordingmedium once data are written onto the data area in a data writingoperation; (b) means for writing data written in the defective area ontoanother area of the data area if the defective area is detected; and (c)means for writing, onto at least one defect management area on therecording medium, defect management information associated with thedefective area.
 42. An apparatus for managing a defective area on arecording medium of writable once type, the recording medium including adata area and a lead-in area, the data area including a spare area, theapparatus comprising: (a) means for detecting an existence of adefective area within the data area of the recording medium afterwriting data onto the data area in a data writing operation; (b) meansfor writing data written in the defective area onto the spare area ifthe defective area is detected; and (c) means for writing, onto thelead-in area, defect list information associated with the defectivearea.